Our Blog on the UK Traffic News Website

Annual Average Daily Flow or AADF for short is one and Traffic Volume is a second way.

Annual Average Daily Flow (AADF) is the daily vehicle average over the course of a year on a particular stretch of road.

Traffic Volume is the total volume of traffic on a stretch of road for the whole year and is calculated by multiplying AADF x length of road x 365 (or 366 in a leap year).

Graph of the UK's Top 10 Busiest Roads During 2013

The graph shows the top 10 UK business roads reading the colour coded descriptions from left to right and downwards.

This above graph actually refers to the top 10 busiest sections of UK roads, highlighting the traffic hotspots.

So the M25 around Junctions 14 and 15 where to two busiest stretches of UK road during 2013.

In fact the M25 between junctions 11 and 16 are the top 5 busiest strectchs of road in the UK with annual average daily flow of all vehicles from 187,116 vehicles at M25 Junction 11 and 12 up to 227,585 vehicles on the Junction 14 to 15 stretch.

Around 72.3 Million passengers arrived at or departed from Heathrow during 2013, which was Heathrow's busiest year on record, of which 26 million or 37% never left the airport taking connecting flights. That still leaves just over 46 million passengers exiting Heathrow airport into the local area during 2013 of which are fair proportion would travel by road. The busiest day on record at Heathrow was 30 June 2013 with 238,949 passengers that day. The average 63% leaving the airport would have meant that around 150,000 exited or aarrived at Heathrow that day, some on public transport into London and others entering the road network locally.

On top of the passangers travelling in and out of Heathrow are the people employed at Heathrow. There are approximately 77,000 people working within the Heathrow Airport boundaries and many more in the local area making the western side of the M25 motorway a very busy stretch of motorway.

The M1 Junctions 7 and 8 (Hatfield and Hemel Hempstead) was the 6th busiest stretch of UK road.

The M60 motorway around Manchester at Junctions 12 and 13 was the 7th busiest stretch of UK road where it connects to the M62 motoway to Liverpool.

The remaining top three of the top 10 busiest stretches of UK roads are on on the western side of the M25 motorway.

Cars and taxi cabs far outnumbering other vehicle types.

List of Top 10 Busiest Roads

A list of roads that have the busiest traffic at some part of that road the list of the top 10 busiest roads would be as follows:

M25 (various junctions)

M1 (junctions 7 and 8 and other junctions)

M60 (junctions 12 and 13 and other junctions)

M8 (junctions 4 to 6)

M4 (junctions 4 and 4B and other junctions)

M6 (junctions 20 and 21 and other junctions)

M56 (junctions 3 and 4)

M61 (junctions 2 and 3)

A406 (Redbridge and Waltham Forest)

M42 (junctions 6 to 7A)

But as some of these individual roads stretch a long way with quieter and busier sections a list of this type does not really accurately pin point the traffic hot spots in the same way.

Traffic statistics are based on Department for Transport figures and Heathrow figures are based on Heathrow Airports public facts and figures.